Smooth out Capr endpoints

[mdlavallee92]

From previous issues raised (see #91, #97 ), there are too many ideas on how to coerce a Capr cohort into a circe json. For concept sets we use the as.json command, but for cohorts we use a generic command compile which uses both toCirce and as.json. Need to streamline the ui to generate the Capr endpoint (circe json struc).

Goal: create a single command to coerce capr to circe json that is consistent. Edits required in file.

@xj2193 we have discussed working on this over email. Just recording this as a github issue for tracking purposes.